<!DOCTYPE html>
<html>
	<head>
		<meta charset="utf-8">
		<title></title>
		<style>
			*{
				margin: 0;
				padding: 0;
			}
			a{text-decoration: none;}
			ul li{list-style: none;}
			img{vertical-align: top;}
			.box{
				width: 800px;
				height: 800px;
				margin: 50px auto;
				border: 1px solid #000000;
				
			}
			.box .box2{
				position: relative;
				width: 800px;
				height: 600px;
			}
			.box .box2 .top{
				width: 400px;
				height: 400px;
				overflow: hidden;
				
				position: absolute;
				left: 0;
				right: 0;
				top: 0;
				bottom: 0;
				margin: auto;
			}
			.box .box2 .top img{
				width: 400px;
				height: 400px;
			}
			.box ul{
				
				width: 800px;
				height: 200px;
				
			}
			.box ul li{
				float: left;
				width: 199px;
				height: 200px;
				border-right:1px solid black;
				border-top:1px solid black;
			}
			.box ul li a img{
				display: block;
				width: 199px;
				height: 200px;
			}
			.box ul li a img:hover .top img{
				z-index: 999;
			}
		</style>
	</head>
	<body>
		<div class="box">
			<div class="box2">
			<div class="top">
				<img src="../img/1.jpg" id="i1">
				<img src="../img/2.jpg" id="i2">
				<img src="../img/3.jpg" id="i3">
				<img src="../img/1.jpg" id="i4">
			</div>
			</div>
			<ul>
				<li><a href="#i1"><img src="../img/1.jpg"/></a></li>
				<li><a href="#i2"><img src="../img/2.jpg"/></a></li>
				<li><a href="#i3"><img src="../img/3.jpg"/></a></li>
				<li><a href="#i4"><img src="../img/4.jpg"/></a></li>
			</ul>
		</div>
	</body>
</html>
